Technical Field
The present invention relates generally to optimizing power flows in energy distribution systems, and more particularly, to a system and method for optimizing power flows using a harmony search with machine learning.
Description of the Related Art
Voltage regulation is an important factor in electrical distribution systems as energy utility companies must keep customers' service voltage (e.g., voltage at the customer's meter, load side of point of common coupling (PCC)) within acceptable ranges. Voltage regulation may include power system modeling and/or system power flow calculations for use in planning and/or operation of power systems. Power flow calculations may be employed in attempts to optimize distribution of power. For example, network reconfiguration, service restoration, capacitor placement, etc, may require calculating a large number (e.g., hundreds, thousands, etc.) of power flow problems when planning and/or controlling distribution of power in a power distribution system.
Grid-connected energy storage systems (ESSs) are a fast growing global market. Recently, increases in the penetration of renewable energy resources into grid-connected ESSs have presented a challenge to the traditional design and operation of electric power systems. The existing power grid was designed for centralized power generation with unidirectional power flow. With renewable energy (or any other type of distributed generation of electricity), power is effectively generated everywhere and flows in multiple directions. However, the intermittent and highly variable nature of distributed generation causes power quality and/or reliability issues, which leads to increased energy costs. Furthermore, a critical problem is a wide variation of system voltage. For example, as the load continues to increase, utilities attempt to push the grid to transfer more and more power, which may lead to power distribution problems, including, for example, unbalanced power flows.
Conventionally, models of systems including unbalanced power flows have been employed to describe/simplify power distribution systems for use in planning and/or controlling distribution of power. However, conventional unbalanced power flow models are nonlinear with integer variables, and as such, are extremely difficult and processor intensive to solve for large-scale distribution systems (e.g., shopping malls, cities, etc.). Power applications in distribution systems with unbalanced multi-phase power flows are becoming more prevalent, and computation speed of power flow calculations are an obstacle for attaining optimal and sustainable power supply (e.g., for industrial applications) with unbalanced power flows. Moreover, although conventional systems have employed harmony search methods in single-phase optimal power flow problems, conventional methods cannot be effectively applied to unbalanced multi-phase power flows.